Determining whether one array contains the contents of another array in JavaScript/CoffeeScript
arrays, coffeescript, javascript
Solution
No set function does this, but you can simply do an ad-hoc array intersection and check the length.
[8, 1, 10, 2, 3, 4, 5, 9].filter(function (elem) {
return arr1.indexOf(elem) > -1;
}).length == arr1.length
A more efficient way to do this would be to use `.every` which will short circuit in falsy cases.
arr1.every(elem => arr2.indexOf(elem) > -1);
Problem
In JavaScript, how do I test that one array has the elements of another array? ``` arr1 = [1, 2, 3, 4, 5] [8, 1, 10, 2, 3, 4, 5, 9].function_name(arr1) # => true ```